4 BR. COLLETT. [No. 83. 

gion of the coniferous woods. The species occurs more or less nume- 
rously throughout the south of Norway, is found in several parts 
of Central Sweden, and is, besides, dispersed throughout North- 
ern Russia, and Central Siberia, as far as the Sea of Okhotsk. 
Out of Norway, M. lemmus is distributed throughout Swe- 
dish and Russian Lapland, but its range eastward ceases on the 
western shores of the White Sea; and, notwithstanding that it 
is spread over the greatest portion of the Kola Peninsula, it does 
not seem to habitually appear so far to the eastward as Arch- 
angel. 
To the eastward of the White Sea its place is oceupied by 
D. obensis; but the distribution of the two species in those dis- 
tricts where they meet, has not, as yet, been fully demonstrated. . 
In N. W. Russia it reaches its southern limits in the Lapland 
districts of Kemi, Muonio and Torneå; in Sweden it occurs on 
the mountains of the Swedish-Norwegian frontier, and has hardly 
been met with south of Wermeland (61. N. Lat.). 
M. lemmus, as is known, has been found in a fossil state 
in the post-pliocene formations (the glacial period), together with 
remains of other arctic mammals! and birds, as far south as 
Saxony, and likewise in England. 


1 Amongst, which the allied genus Cuniculus torguatus. 
